Refactored validation logic into SettingsValidator class

This commit decomposes the validation logic previously located in the `GenerateCommand` class, and moves it into its own `SettingsValidator` class for better organization and reusability. This provides a cleaner architecture and easier future maintenance, as now settings validation can be altered independent from command generation logic.

src/Refitter/GenerateCommand.cs

@@ -19,50 +19,8 @@ public override ValidationResult Validate(CommandContext context, Settings setti
  if (!settings.NoLogging)
  Analytics.Configure();
 
- if (string.IsNullOrWhiteSpace(settings.OpenApiPath) &&
- string.IsNullOrWhiteSpace(settings.SettingsFilePath))
- return ValidationResult.Error("Input or settings file is required");
-
- if (!string.IsNullOrWhiteSpace(settings.OpenApiPath) &&
- !string.IsNullOrWhiteSpace(settings.SettingsFilePath))
- return ValidationResult.Error(
- "You should either specify an input URL/file directly " +
- "or use specify it in 'openApiPath' from the settings file, " +
- "not both");
-
- if (!string.IsNullOrWhiteSpace(settings.SettingsFilePath))
- {
- var json = File.ReadAllText(settings.SettingsFilePath);
- var refitGeneratorSettings = Serializer.Deserialize<RefitGeneratorSettings>(json);
- settings.OpenApiPath = refitGeneratorSettings.OpenApiPath;
-
- if (string.IsNullOrWhiteSpace(refitGeneratorSettings.OpenApiPath))
- return ValidationResult.Error(
- "The 'openApiPath' in settings file is required when " +
- "URL or file path to OpenAPI Specification file " +
- "is not specified in command line argument");
-
- if (!string.IsNullOrWhiteSpace(settings.OutputPath) && 
- settings.OutputPath != Settings.DefaultOutputPath &&
- (!string.IsNullOrWhiteSpace(refitGeneratorSettings.OutputFolder) || 
- !string.IsNullOrWhiteSpace(refitGeneratorSettings.OutputFilename)))
- return ValidationResult.Error(
- "You should either specify an output path directly from --output " +
- "or use specify it in 'outputFolder' and 'outputFilename' from the settings file, " +
- "not both");
- }
-
- if (!string.IsNullOrWhiteSpace(settings.OperationNameTemplate) &&
- !settings.OperationNameTemplate.Contains("{operationName}") &&
- settings.MultipleInterfaces != MultipleInterfaces.ByEndpoint)
- return ValidationResult.Error("'{operationName}' placeholder must be present in operation name template");
-
- if (IsUrl(settings.OpenApiPath!))
- return base.Validate(context, settings);
-
- return File.Exists(settings.OpenApiPath)
- ? base.Validate(context, settings)
- : ValidationResult.Error($"File not found - {Path.GetFullPath(settings.OpenApiPath!)}");
+ return new SettingsValidator()
+ .Validate(context, settings);
  }
 
  public override async Task<int> ExecuteAsync(CommandContext context, Settings settings)
@@ -192,10 +150,4 @@ private static void TryWriteLine(
  // ignored
  }
  }
-
- private static bool IsUrl(string openApiPath)
- {
- return Uri.TryCreate(openApiPath, UriKind.Absolute, out var uriResult) &&
- (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps);
- }
 }

src/Refitter/SettingsValidator.cs

@@ -0,0 +1,116 @@
+using Refitter.Core;
+
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace Refitter;
+
+public class SettingsValidator
+{
+ public ValidationResult Validate(CommandContext context, Settings settings)
+ {
+ if (BothSettingsFilesAreEmpty(settings) || BothSettingsFilesArePresent(settings))
+ {
+ return GetValidationErrorForSettingsFiles();
+ }
+
+ return !string.IsNullOrWhiteSpace(settings.SettingsFilePath)
+ ? ValidateFilePath(settings)
+ : ValidateOperationNameAndUrl(settings);
+ }
+
+ private static bool BothSettingsFilesAreEmpty(Settings settings)
+ {
+ return string.IsNullOrWhiteSpace(settings.OpenApiPath) &&
+ string.IsNullOrWhiteSpace(settings.SettingsFilePath);
+ }
+
+ private static bool BothSettingsFilesArePresent(Settings settings)
+ {
+ return !string.IsNullOrWhiteSpace(settings.OpenApiPath) &&
+ !string.IsNullOrWhiteSpace(settings.SettingsFilePath);
+ }
+
+ private static ValidationResult GetValidationErrorForSettingsFiles()
+ {
+ return ValidationResult.Error(
+ "You should either specify an input URL/file directly " +
+ "or use specify it in 'openApiPath' from the settings file, " +
+ "not both");
+ }
+
+ private ValidationResult ValidateFilePath(Settings settings)
+ {
+ var json = File.ReadAllText(settings.SettingsFilePath!);
+ var refitGeneratorSettings = Serializer.Deserialize<RefitGeneratorSettings>(json);
+ settings.OpenApiPath = refitGeneratorSettings.OpenApiPath;
+
+ return ValidateFileAndOutputSettings(settings, refitGeneratorSettings);
+ }
+
+ private ValidationResult ValidateFileAndOutputSettings(
+ Settings settings,
+ RefitGeneratorSettings refitGeneratorSettings)
+ {
+ if (string.IsNullOrWhiteSpace(refitGeneratorSettings.OpenApiPath))
+ {
+ return GetValidationErrorForOpenApiPath();
+ }
+
+ if (!string.IsNullOrWhiteSpace(settings.OutputPath) &&
+ settings.OutputPath != Settings.DefaultOutputPath &&
+ (!string.IsNullOrWhiteSpace(refitGeneratorSettings.OutputFolder) ||
+ !string.IsNullOrWhiteSpace(refitGeneratorSettings.OutputFilename)))
+ {
+ return GetValidationErrorForOutputPath();
+ }
+
+ return ValidateOperationNameAndUrl(settings);
+ }
+
+ private static ValidationResult GetValidationErrorForOpenApiPath()
+ {
+ return ValidationResult.Error(
+ "The 'openApiPath' in settings file is required when " +
+ "URL or file path to OpenAPI Specification file " +
+ "is not specified in command line argument");
+ }
+
+ private static ValidationResult GetValidationErrorForOutputPath()
+ {
+ return ValidationResult.Error(
+ "You should either specify an output path directly from --output " +
+ "or use specify it in 'outputFolder' and 'outputFilename' from the settings file, " +
+ "not both");
+ }
+
+ private ValidationResult ValidateOperationNameAndUrl(Settings settings)
+ {
+ if (!string.IsNullOrWhiteSpace(settings.OperationNameTemplate) &&
+ !settings.OperationNameTemplate.Contains("{operationName}") &&
+ settings.MultipleInterfaces != MultipleInterfaces.ByEndpoint)
+ {
+ return GetValidationErrorForOperationName();
+ }
+
+ return IsUrl(settings.OpenApiPath!) ? ValidationResult.Success() : ValidateFileExistence(settings);
+ }
+
+ private static ValidationResult GetValidationErrorForOperationName()
+ {
+ return ValidationResult.Error("'{operationName}' placeholder must be present in operation name template");
+ }
+
+ private ValidationResult ValidateFileExistence(Settings settings)
+ {
+ return File.Exists(settings.OpenApiPath)
+ ? ValidationResult.Success()
+ : ValidationResult.Error($"File not found - {Path.GetFullPath(settings.OpenApiPath!)}");
+ }
+
+ private static bool IsUrl(string openApiPath)
+ {
+ return Uri.TryCreate(openApiPath, UriKind.Absolute, out var uriResult) &&
+ (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps);
+ }
+}